""" 
@Version: 0.1
@FileName    :    for3
@Author      :    kx
@CreateTime  :    2021/7/6 18:10 
@Description :    计算n！
"""

n = int(input('n = '))
result = 1
for x in range(1, n + 1):
    result *= x
    # print('%d! = %d' % (n,result))
print('%d! = %d' % (n,result))